1. Field of the Invention
The prevent invention relates to an anti-fogging structure for a headlight lamp.
2. Description of the Related Art
An anti-fogging structure for the headlight lamps of a vehicle or the like, as disclosed, for example, in Japanese Unexamined Patent Application, First Publication, No. 2001-10403, draws air inside the headlight lamp from an intake opening and discharges it from a discharge opening. In addition, Japanese Unexamined Patent Application, First Publication, No. Hei 11-86614, discloses a structure in which the air in a headlight lamp housing is smoothly discharged to the outside from an air hole by preventing circulation of air in the headlight lamp housing.
However, in the conventional anti-fogging structure for a headlight lamp described above, because the conditions in which the left and right headlight lamps are placed are subtly different, there is the problem that a difference in the performance of the condensation on the left and right headlight lamps occurs.
For example, in a normal vehicle having a radiator fan that rotates in a predetermined direction, a bias occurs in the pressure conditions where the left and right headlight lamps are placed, and in addition, in a vehicle having a structure wherein the engine, which is a source of heat, is disposed offset to either the left or right, a bias occurs in the temperature conditions in which the left and right headlight lamps are placed, and there is the problem that this causes an unevenness in the anti-fogging performance of the left and right headlight lamps.
Thus, this invention provides uses a structure in which the unevenness in the anti-fogging performance of the left and right headlight lamps is eliminated and the anti-fogging performance is improved by using a structure in which the breathing mechanism of the left and right headlight lamps differ in conformity to the differing conditions in which the left and right headlight lamps are placed.